Overview
The STEF12SPUR is an integrated electronic fuse designed by STMicroelectronics to monitor and protect 12 V DC power lines. This device is optimized to detect and react to overcurrent and overvoltage conditions, ensuring the safety and reliability of the power supply system. When connected in series to the main power rail, it can limit the output current to a safe value defined by the user and disconnect the load from the power supply if an anomalous overload condition persists. The STEF12SPUR also features undervoltage lockout, thermal protection, and adjustable turn-on slew-rate to control in-rush current during startup and hot-swap operations.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Power Supply Voltage (VCC) | 10 to 13.8 | V |
| Maximum Continuous Current (ID) | 3.5 | A |
| Output Overvoltage Clamp (VClamp) | 13.8 to 16.2 | V |
| Undervoltage Lockout (VUVLO) | 7.7 to 9.3 | V |
| On-Resistance (RDSon) | 40 to 50 mΩ (TJ = 25°C) | mΩ |
| Thermal Shutdown (TSHDN) | 165°C | °C |
| Package | TSOT23-8L, DFN10 (3x3 mm) | |
| Operating Temperature Range | -40 to 125°C | °C |
Key Features
- Adjustable current limit
- Thermal protection
- Input undervoltage lockout
- Low inrush current during startup
- Integrated 40 mΩ Power FET
- En/fault pin for status indication and control
- Adjustable slew rate for output voltage
- Gate control pin for reverse current blocking FET (DFN10 package)
- Latch (STEF12S) or autoretry (STEF12SA) versions
- UL2367 Recognized and IEC 62368-1 CB certified
Applications
- Hard Disk and SSD drives
- Hard disk array
- Hot-swap board
- Hot-plug protection
Q & A
- What is the primary function of the STEF12SPUR?
The STEF12SPUR is an integrated electronic fuse designed to monitor and protect 12 V DC power lines by detecting and reacting to overcurrent and overvoltage conditions.
- What are the operating voltage and current limits of the STEF12SPUR?
The operating power supply voltage is 10 to 13.8 V, and the maximum continuous current is 3.5 A at 25°C.
- How does the STEF12SPUR handle overvoltage conditions?
The device regulates the output to a preset safe value, typically clamping at 15 V, when an overvoltage condition is detected.
- What is the purpose of the undervoltage lockout feature?
The undervoltage lockout prevents the load from malfunctioning by keeping the device off if the rail voltage is too low.
- How does the STEF12SPUR manage thermal protection?
The device features thermal protection that turns off the power MOSFET and disconnects the load if the device temperature exceeds 165°C.
- What packages are available for the STEF12SPUR?
The STEF12SPUR is available in TSOT23-8L and DFN10 (3x3 mm) packages.
- Can the STEF12SPUR be used in hot-swap applications?
Yes, the STEF12SPUR features adjustable turn-on slew-rate to control in-rush current during startup and hot-swap operations.
- How does the reverse current blocking function work?
The device provides a dedicated gate drive signal on the VG pin to control an external blocking MOSFET for reverse current protection in case of input voltage loss.
- What certifications does the STEF12SPUR hold?
The STEF12SPUR is UL2367 Recognized and IEC 62368-1 CB certified.
- Can multiple STEF12SPUR devices be connected for simultaneous shutdown?
Yes, the EN/Fault pin can be connected to other devices to achieve simultaneous enable/disable functionality during thermal faults or other events.
